Optical fibers are used in an increasing number and variety of applications, such as a wide variety of telecommunications and data transmission applications. As a result, fiber optic networks must include an ever increasing number of enclosures in which one or more of the optical fibers are interconnected or otherwise terminated. For example, fiber optic networks, such as cable television (CATV) networks, may include a number of optical network units (ONUs) in which the optical signals propagating along the optical fibers are converted to respective electrical signals. In addition, telephone and CATV networks can include a number of network interface devices (NIDs), one of which is associated with each subscriber. Upon receiving the incoming optical signals, the NID splits and routes the signals to predetermined locations, such as to various telephone or CATV outlets. Like an ONU, the NID can also convert the incoming optical signals to electrical signals, if necessary. Fiber optic networks can also include a number of splice closures in which various ones of the optical fibers are spliced or optically connected.
These enclosures protect the optical fibers, such as from moisture or other forms of environmental degradation. These enclosures also isolate or otherwise protect the optical fibers within the enclosure from strain or torque imparted to a portion of the fiber optic cable outside of the enclosure in order to maintain proper alignment and spacing between the spliced optical fibers and to prevent undesirable signal attenuation.
These enclosures, such as ONUs, NIDs and splice closures, typically include a number of receptacles in which the individual optical fibers of a fiber optic cable are connected to respective optical fibers within the enclosure. The optical fibers within the enclosure can then be interconnected or otherwise terminated as desired. Conventionally, receptacles have included an externally threaded sleeve fixed to and extending outward from the enclosure. In order to provide for interconnection of the optical fibers, a ferrule holder can be disposed within the externally threaded sleeve. The ferrule holder defines one or more openings for receiving respective ferrules and for maintaining the ferrules in a predetermined position relative thereto. The ferrules are, in turn, mounted upon the end portions of one or more optical fibers which extend into the interior of the enclosure.
In order to mate with the receptacle of a conventional enclosure, a fiber optic connector assembly, typically referred to as a plug, is mounted upon the end portion of a fiber optic cable. Typically, the plug includes a generally cylindrical housing and a ferrule holder disposed within the cylindrical housing. The ferrule holder of the plug also defines one or more openings for receiving respective ferrules and for maintaining the ferrule in a predetermined position relative thereto. The ferrules are, in turn, connected to one or more optical fibers of the fiber optic cable such that mating of the plug and the receptacle will align or connect the optical fibers of the fiber optic cable with respective optical fibers within the enclosure.
Following the connection of a plug with a receptacle, it is sometimes desirable to remove certain ones of the ferrules. For example, a ferrule or the optical fibers upon which a ferrule is mounted may be damaged and may need to be replaced. Alternatively, a ferrule may need to be removed in order to clean the ferrule and, more particularly, to clean the end faces of the optical fibers upon which the ferrule is mounted. In instances in which the receptacle was not fully populated with ferrules, it may be desirable to insert additional ferrules into the receptacle so as to establish additional optical connections following connection of the plug with the receptacle.
In order to remove a ferrule or to insert an additional ferrule following the connection of a plug with a conventional receptacle, the plug must first be disconnected, thereby optically disconnecting all of the optical fibers. The receptacle must then be at least partially disassembled in order to access the individual ferrules. Only after disconnecting the plug from the receptacle and at least partially disassembling the receptacle can a technician access one or more of the ferrules in order to make the necessary repair or replacement or to insert an additional ferrule into the receptacle. As will be apparent, the disconnection of the plug from the receptacle and the attendant disconnection of each of the optical fibers can create significant problems in instances in which the optical signals carried by the optical fibers are of vital importance. Even if the optical signals are not of vital importance, the disconnection of all of the optical fibers significantly delays the optical communications including the optical communications supported by the optical fibers that are not being repaired or replaced.